System for producing music



6 .5. YOUNG SYSTEM FOR PRODUCING MUSIC Sept. 15, 1931.

Filed May 22, 1930 Inventor: Charles J. Young,

His Attorney.

PatentedSept. 15, 1931 UNITED STATES PATENT; OFFICE I CHARLES J. YOUNG, OF ABDMOBE, PENNSYLVANIA, ASSIGNOB TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK SYSTEM FOR PR ODUCING MUSIC Application filed Kay 22,

My invention relates to systems for electrically producing music, and it has for one of its ob ects to provide a system of the type indicated which is capable of producing either pure musical tones, or complex tones,

and tones having desired quality as determined by the presence of multiple tones and overtones, in proportions determined by the skill and manipulation of the operator.

A further object of the invention is to provide, in a system for producing music, means whereby a plurality of different tones may be simultaneously produced. In accordance with the invention the different tones simultaneously produced may be tones of the same octave, or of different octaves, as, for example, overtones, and may vary over a wide range both in pitch and intensit A further object of the invention is to provide a system which is economical in construction and in which the number of oscillation sources, which in the system to be described comprise electron discharge devices, is materially reduced over systems of the prior art.

Still another object of the invention is'to provide a system which may be readily adusted, or tuned, to produce the desired tones. Thus in accordance with my invention means are provided whereby corresponding notes of all of the different octaves may besimultaneously adjusted by a single operation; i. e. u on ad ustment of the different notes of a single octave the notes of each'of the other octaves are automatically adjusted. In this way the tuning process is materially simplified and ease in adjustment of the system to produce the various musical scales demanded by the operator, is secured.

Another object of the invention is to provide a system in which the different tones areproduced as a result of beating together a plurality of oscillations having different high frequencies whereby the system may be controlled with the facility and flexibility with which the circuits of the high frequency sources may be controlled.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims.

1930. Serial No. 454,810.

My invention itself, however, both as to its organization and method of o eration, togcther with further ob'ects an advantages thereof may best be un erstood by reference to the following description taken in connection with the accompanying drawing, in which the single figure represents an embodiment of my invention.

In accordance with my invention the various notes of a single octave of the musical scale are produced by selectively combining or beating to ether, oscillations roduced by a fixed hlgh requency source, w ich I shall hereinafter term an octave source, and other oscillations having a pluralit of different frequencies in accordance wit the different tones or notes which are to be produced. These other oscillations may be produced in any known way -for producing oscillations having different frequencies. As shown in the drawing these oscillations are produced by a pluralit of fixed sources, which I shall hereinafter term the note source, circuit arran ments being provided whereby oscillations aving the fundamental frequency of the first-mentioned fixed high frequency source ma be selectively combined with any of the latter. In this way all of the desired notes of a given octave may be produced.

In order to produce the various notes of hi her octaves circuit arran ements are rovlded in accordance with m invention whereby. desired harmonics of t e first-mentioned octave source may be selectively combined with the corresponding harmonic of a desired note source. Thus by combining the fundamentals, second harmonics, or corresponding higher harmonics of the first-menacross this resistance, and is arranged to supply amplified oscillations to a sound-producing device or loud speaker 14. The oscillating detectors 1 5 etc. are arranged to produce oscillations of high frequency, preferably, of frequencies in the radio or inaudible range, and the frequencies produced by the different oscillators differ in accordance with the difierence in pitch of the various notes to be produced.

While I have shown in the drawing only five of these sources, it will of course be understood that the number of sources employed in this group will correspond with the numher of notes which are to be produced in the various octaves as, for example, twelve.

At 15, 16 17, I have shown a second group of high trequency oscillation generators which I choose to term the octave sources of the system. The oscillations produced by the source 15 -.is of inaudible frequency and differs from ie'frequency produced by the source 1 by; mount corresponding to the lowest tone which is to be produced. The sources 16, 17 etc. are harmonic amplifiers, of -frequency doublers, the source 16 being supplied with oscillations from source 15, and source 17 being supplied with -oscillations from source 16;- and so on, in succession, through the octav groups. That is, as shown in the drawing, dscillations from the source 15' are supplied to the gri circuit of the s"ource 16 and the a ode cir it of this source is tuned to double th re ency of the source 15. will appear the second harmonic of the source 15. Similary in the output circuit of the source 17 will appear oscillatiohsgwhich are double the frequency of the source 16. Thus, in the output circuit of the source 17 will appear oscillations corresponding to,the second harmonic at the source 16, or" the fourth harmonic of the source 15.

By means of the bracket18 I have designated in the drawing a system of cross-connections employing'keys19-23, etc. -19'23', etd; 19"-23" etc. whereby the output circuit from any of the octave sources 15, 16, 17, may be selectively connected to the input circuit of-any of the note sources 1 to5. In this way it is possible to produce each of the different notes of the various octaves.

It will be seen from an inspection of the system of cross-connections that one side of all of the inputcircuits of the note sources are connected together and to one side of the output circuits of all of the octave sources through conductors 24, 25, 26. One group of keys 19 to 23 etc. is associated with the output circuit of each of the octave sources and the number of keys in each of these groups corresponds to the number of note sources or to the number of notes to be produced in the various octaves. These keys may accordingly, if desired, be arranged in the manner of the notes of a piano.

Thus in the anode circuit of the source 1.6

These keys are so connected that upon operation of any key in any group the note source to which the operated key is connected, is connected to the octave source wit-h which the group of keys is associated. That is, upon operation of any key the side of the output circuitopposite to the conductor 26 of the octave source with which the group containing the operated key is associated may be selectively connected to the side opposite to conductor 24 of the input circuit of the note source corresponding to theoperated key.

Thus, for example, to produce the lowest note of the first octave, key 19 will be operated. The output 15 of the source 15 will then be connected directly to the input 1' of the source 1 through key 19 and conductors 24, 25 and 26. As was previously stated these two sources differ in frequencies by an amount corresponding to the lowest note which is to be produced. The grid of the discharge device 1 is biased negatively sufficiently to cause this device to operate also as a detector, as is already understood, and, accordingly, in the output circuit of the source 1 will appear oscillations having the beat frequency between the oscillations produced bythe source 15 zmhose produced by the source 1. These oscillations of beat frequency will be supplied to the circuit 11, amplified by the amplifier 13 and thence supplied to the loud speaker 14. To produce the next higher tone, key 20 will be operated, thereby connecting the output circuit 15 in circuit with the input circuit 2'. Since the fundamental frequency of the note source 2 differs from that of the octave source 15 by an amount corresponding to that of the next higher note, this note will be produced by the loud speaker 14. Similarly by operating each of the various keys 1923 etc. f the group associated with octave source 1 each of the various notes of the first octave will be produced.

In order that each of the notes of the first and succeeding octaves shall have the same,

ordgired, intensity, adjustment means com- PIlSlIlg resistances 2731, etc. are provided, each of these resistances being connected 1n shunt with the input to one of the note sources. In a corresponding manner, means comprising resistances 32, 33, 34, etc., one for each octave, are rovided whereby the overall intensity of tiie different octaves may be properly adjusted, with relation to each other. Thus by means of these resistances the intensity of the individual components of a multiple note may be independently controlled whether these components comprise diflerent tones of the same octave or tones of different octaves as, for example, overtones.

It will be apparent from the drawing that if desired two or more of the keys 19, to 23, 19' to 23', 19" to 23", etc. may be simultaneously pressed, thereby producing a combination of notes, or a multiple or complex note, that is, amusical chord from the loud speaker 14.

. The note sources 1 to 5 etc. are each designed, as by construction of the windingsand proper adjustment of the voltages, to produce oscillations which are rich in harmonics.

These harmonics are utilized inaccordance lations produced by the source 16 will beat with the second harmonic of the oscillations produced bythe note source 1 and, accordingly the lowest note of the second octave will be produced'by the loud speaker 14'. Similarlygthe lowest note of the thirdoctave may be produced by operation'of key 19 thereby causing the oscillations produced by source 17 to beat with the fourth harmonic of the oscillations produced by source 1. Of course any other note of each of the different octaves may be produced by operating the proper key of the corresponding octave group.

To produce a desired tone plus desired harmonics, or overtones thereof, corresponding keys of a plurality of octave groups may be operated. Thus, for example, if keys 19 and 19' are simultaneously operated the lowest note of the first octave and its first overtone will be produced from the loud speaker.

The tuning condensers 35-39, etc. of the individual note sources, and tuning condenser 40-42 etc. of the octave sources are shown as variable. The individual condensers of the note sources may be adjusted or, if desired, by, means of a suitable Vernier, to tune the instrument to produce the desired notes,' each of these condensers of course simultaneously adjusting a corresponding note in each octave. The overall pitch of the system may be adjusted within certain limits by condenser 40 of the source 15. Preferably, however, this adjustment may be effected by means of a suitable unicontrol upon condensers 35-39 etc. and a construction of these condensers such that the frequencies of each of these sources are effected in proportional amounts. Such a unicontrol is indicated in the drawing by dotted line 43.

While, for the purpose of simplicity of the drawin the various oscillation sources have been s 1OWI1 as of a simple conventional design, it will of course be understood that these sources may be of any suitable construction for the purposes contemplated. Similarly low-pass filters in the output circuits of the various sources, particularly, of the octave sources for suppressing frequencies which are higher than those desired, and amplifiers in the circuit where desired may be employed. Such amplifiers and filters are not shown in the drawing since their use in the circuit if found necessary in any equipment will be well understood by persons skilled in the art.

Further, while I have suggested an arrangent of the keys, 19-23; 1923; 19"- 23",-etc. in the nature of the keys of a piano, it will be understoom that I do not wish to be limited thereto since many different arrangements of these keys and also of the controls for resistances 27-31, etc. and

32-34, etc. will suggest themselves in accordance with the particular requirements of different systems. Thus a system, in accordance with my invention, for producing a large -number of notes of relatively pure composition will, desirably, employ a different arrangement of controls from one adapted to produce a fewer number of notes but in which each note is relatively rich in controllableharmonics. The overall volume of sound produced by-the system may, of course, be controlled by potentiometer 12.

Vhile in the drawing I have shown a particular embodiment of the invention, it will of course be understood that I do not wish to be limited thereto, since many modifica= tions maybe made, both in the circuit arrangement and in the instrumentalities employed. I contemplate, therefore, by the appended claims to cover any such modificatidns as fall within the true spirit and scope of my invention.

What I claim as 'new and desire to secure by Letters'Patent of United States, is:

1. In combination, means for producing oscillations of hi h fundamental frequency and oscillations aving frequencies corresponding to certain of theharmonics thereof, means for producing oscillations of a frequency differing from said fundamental by an amount corresponding to a musical tone and for producing oscillations having frequency corresponding to certain of the liarmonicsthereof, and means for selectively producing a beat frequency between the oscillations of said fundamental frequencies and between-corresponding harmonics thereof. I

2. In combination, means for producing oscillations of high fundamental frequency and oscillations having frequencies corresponding to certain of the harmonics thereof, means for producing oscillations of frequency differing from said fundamental'by an amount corresponding to a musical tone and producing oscillations having frequency corresponding to certain of the harmonics thereof, and means for selectively producing a beat frequency between the oscillations of said fundamental frequencies and between corresponding harmonics thereof, and means for independently controlling the intensity lations having a plurality of different fun-' damental frequencies, said frequencies differing in accordance with the tones to be produced'and for producing harmonics of each of said fundamental frequencies, means for producing oscillations having a different fundamental frequency, said frequency differing from the lowest frequency produced by said first means by an amount corresponding to the lowest tone to be produced and for producing harmonics of oscillations of said different fundamental frequency, and means whereby oscillations of said different fundamental frequency may be caused to beat with oscillations of any of said first-mentioned fundamental frequencies and where- 'by certain of the harmonics of said difierent fundamental frequency may be caused to beat with a corresponding harmonic of any of said first-mentioned fundamental frequencies.

4. The combination, in a system for producing music, of means for producing oscillations having a plurality of different fundamental frequencies, said frequencies differing in accordance with the tones to be produced and for producing harmonics of each of said fundamental frequencies, means for producing oscillations having a different fundamental frequency, said frequency differing from the lowest frequency produced by said first means by an amount corresponding to the lowest tone to be produced and for producing harmonics of oscillations of said different fundamental frequency, and means whereby oscillations of said diflerent fundamental frequency may be caused to beat with oscillations of any of said first-mentioned fundamental frequencies and whereby certain of the harmonics of said different fundamental frequency may be caused to .beat with a corresponding harmonic of any of said' first-mentioned fundamental frequencies, and means for independently controlling the intensit of each of the beat frequencies produce 5. The combination, in a system for producing music, of a plurality of note sources,

' of oscillations, a plurality of ocatve sources of oscillations, said note sources beingadapted to produce oscillations having fundamental frequencies difi'ering in accordance with the notes of an octave, and to produce harmonics thereof, and said octave sources being adapted to produce oscillations differing by amounts in accordance with the different octaves to be produced, and means for producing beat frequencies between each of said octave sources and any of said note sources whereby any note of a desired octave may be produced.

said frequencies, and said octave sources being adapted to produce oscillations differing by amounts in accordance with the different octaves to be produced, and the lowest frequency produced by said octave sources differing from the lowest frequency producd by said note sources byan amount corresponding to the lowest note to be produced and cross-connections whereby any octave source may be associated with any note source to produce a beat frequency corresponding to any note of each of the octaves.

7 In combination, a plurality of detectors, each of said detectors having an input circuit, means for producing oscillations having a fixed high fundamental frequency and certain of the harmonics thereof in each of said detectors, the fundamental frequency of the oscillations produced in the different detectors differing in accordance with the notes to be produced, means for applying to the input of each detector oscillations differing in frequency from thefirst-mentioned oscillations of fundamental frequency produced in the respective detector by an amount corresponding to a tone to be produced and also certain harmonics thereof, means for selectively controlling said last means separately to supply the fundamental and any harmonic thereof to each detector, an output circuit for each detector and sound producing means associated with said output circuits. 1

8. The combination, in a system for pro- 105 ducing music, of a plurality of note sources of oscillations, a plurality of octave sources of oscillations, said note sources being adapted to produce oscillations having fundamental frequencies difi'ering in accordance 110 with the notes of an octave and to produce harmonics thereof, and said octave sources being adapted to produce oscillations differing by amounts in accordance with the different octaves to be produced, each of said oc- 115 tave sources having an output circuit and each of said note sources having an input circuit, means whereby each input circuit may be selectively connected to any of said output circuits whereby oscillations from 120 any octave source may be supplied to any note source. and a volume control device associated with each of said output circuits.

In witness whereof, I have hereunto set my hand this fourteenth day'of May, 1930.

CHARLES J. YOUNG. 

